1. Field
The present disclosure relates to a lens holding-and-aligning seat and an LED light panel thereof, in particular relates to an aligning seat capable of aligning with the LED by a reflow soldering self-alignment mechanism and a light panel thereof.
2. Related Art
An LED (Light Emitting Diode) has the advantages of power saving and environmental friendly, so the application of the LED is developed from the low-power indicator and display to the high-power illumination field. In the application field of high-power illumination, the LED needs to satisfy the basic requirement of high illumination and additionally the light emitted by the LED lamp must meet a certain illumination requirement. For example, when the LED lamp is applied in the street light, the light intensity distribution must conform to the illumination specification of the street light. Also, when the LED is applied in the head light, the LED heat light must conform to the light shape and intensity specification of the heat light. In addition, in certain low-power applications of the LED, the entire light shape and intensity distribution have specific requirements.
Normally, the LED satisfies the requirements of the light shape and intensity distribution by the design of lens. A part of the design adopts a primary optical architecture and other design adopts a secondary optical architecture. The primary optical architecture refers to directly forming a lens on an LED chip to control the light before the light emitted by the LED chip enters the air. The secondary optical architecture refers to disposing a lens on a light path of the light emitted by the LED chip (normally after the light enters the air) to control the light.
The lens adopted in the secondary optical architecture is generally clamped by a lens holder and the lens holder is fixed on a circuit board in a tight fit, gluing or screw locking manner, and thus the lens is aligned with the LED on the circuit board and controls the light emitted by the LED. Since the alignment between the lens and the LED is maintained by the fixing relation of the lens holder and the circuit board, if the tight fit or screw locking state changes, the overall light shape and intensity distribution are obviously affected.
In regard with the fixing manner of tight fit, normally, several fixing pins on the lens holder are inserted in the holes of the circuit board. Because it is the tight fit (interference fit), an enough force must be exerted to insert the fixing pins in the holes while fitting, if the force is uneven or the dimension relation of the fixing pins and the holes is improper, the alignment is not accurate, which further influences the light shape. Then, since the LED may generate heat in operation, the aperture of the tight fit is usually expanded under the heat, and thus the stable state of the tight fit is changed, which further influences the light shape and intensity distribution.
In regard with the aforementioned gluing and screw locking manners, the processing steps and time must be increased, and in mass production, the alignment effect of the individuals is hard to keep consistent.
Accordingly, the present disclosure provides a lens-holding-and-aligning seat and an LED light panel thereof, which has a precise positioning in the processes thereby solving the above problems.
According to an embodiment, the LED light panel includes a substrate, an LED, a lens and a holding-and-aligning seat. The substrate has a plurality of soldering pads, the LED is disposed on the substrate corresponding to the soldering pad, and the holding-and-aligning seat has a holding portion and a plurality of aligning elements. The holding portion clamps the lens, the aligning elements are soldered on the soldering pads correspondingly by a reflow process, such that the lens corresponds to the LED, and the light shape and light intensity distribution of the light emitted by the LED are adjusted by the lens.
In another embodiment, a surface area of each soldering pad is 1 to 5 times of a bottom area of a corresponding aligning element, and preferably is 1.2 to 5 times.
In an embodiment, the holding-and-aligning seat has a plurality of positioning holes, the aligning elements is disposed on the positioning holes, a difference between a bottom area of each positioning hole and a bottom area of the corresponding aligning element is smaller than or equal to a difference between the bottom area of the aligning element and the area of the soldering pad corresponding to the aligning element.
In an embodiment, the bottom of the holding-and-aligning seat has a plurality of bumps, the substrate has at least a plane corresponding to the bumps, and when the holding-and-aligning seat is fixed on the substrate, one of the bumps touches the plane.
According to an embodiment, the lens-holding-and-aligning seat is applicable to clamping a lens and aligning the lens with an LED on a substrate. The substrate has a plurality of soldering pads. The lens-holding-and-aligning seat includes a body having a holding portion and a plurality of aligning elements. The holding portion clamps the lens, the aligning elements correspond to the soldering pads, such that the lens corresponds to the LED and a surface area of each soldering pad is 2 to 4 times of the bottom area of the corresponding aligning element.
Based on the above characteristics of this disclosure, according to the SMT (Surface-Mount Technology) of the substrate, a solder is firstly coated on the soldering pad by solder printing, then the holding-and-aligning seat (including the aligning element) and the LED are disposed at the proper position (here, mounting, pick and place), such that the aligning element preliminarily corresponds to the soldering pad. Then, the entire substrate, the LED and the holding-and-aligning seat are subjected to a reflow process (or referred to as the Flow Convection Oven), such that the aligning element is bonded on the soldering pad. Because (1) the relative position of the aligning element and the holding-and-aligning seat is determined when designing, (2) the relative position of the LED and the soldering pad is determined on the substrate, and (3) in the reflow process, the aligning element can be precisely aligned on the soldering pad under a binding force and surface tension of the melted solder, the relative position of the lens and the LED is fixed, thereby achieving the purpose of precise positioning.
According to the aforementioned characteristics, the proper design of the bottom area of the aligning element and the surface area of the soldering pad can improve the precision. Further, in another embodiment, when the aligning element and the holding-and-aligning seat do not adopt the tight fit design, the dimension relation between the positioning hole and the aligning element when properly designed may achieve a more precise positioning effect.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed.